Grammar and humor often seem at odds. One does not roll on the floor when a professor points out how to avoid a split infinitive. But there are some knee-slappers in the world of sentence structure:

Original: As a student, a computer is a real help for schoolwork.Revision: A computer really helps students do their schoolwork. or For getting schoolwork done, a computer really helps a student.

Original: Idling among other enormous, gas-guzzling SUVs, the congressman called for higher gas mileage for vehicles like the Fard Motors Extinction.Revision: As a Fard Motors Extinction sat idling among other enormous, gas-guzzling SUVs, the congressmen called for higher gas mileage for such vehicles.

Original: Our church has a preschool program now; those who have children and don't know about it should see Rev. Smith after services today.Revision: Those parents who have not yet heard about the church's preschool program should see Rev. Smith after services today.

You may prefer the originals! It can be enormous fun to purposefully create these types of sentences, but they are guaranteed to lose points when professors spot them in academic writing. Avoiding this problem is easy: think about what the descriptive part of a sentence describes, and be sure the link is clear. Now find and fix misplaced modifiers in these sentences:

The clerk handed the groceries to the customer in a paper bag.

Despite being a murderous cannibal, the professor noted that Dr. Hannibal Lecter is an appealing character in some respects.